Continuation of our work on general methods for the synthesis of macrocyclic lactone antibiotics, using ceric ion oxidation of bicyclic systems with a bridgehead hydroxyl; of the work on new routes to aureomycin and other tetracyclines; of the routes to prostaglandins, especially to those having the correct absolute stereochemistry, from optically active natural sugars; and new simple synthetic pathways to steroids via regiospecific annelation procedures.